Funisitis in term pregnancy is associated with microbial invasion of the amniotic cavity and intra-amniotic inflammation

Objective. Funisitis is the histologic counterpart of the fetal inflammatory response syndrome, which is a multisystemic disorder associated with impending preterm delivery and adverse neonatal outcome. The purpose of this study was to examine the relationship between funisitis and the microbiologic status of amniotic fluid (AF) and AF white blood cell (WBC) count in patients at term. Methods. The relationship between the presence of funisitis, AF culture, and AF WBC count was examined in 832 consecutive patients who delivered a term neonate within 72 hours of amniocentesis. AF was cultured for aerobic and anaerobic bacteria, as well as for mycoplasmas. Funisitis was diagnosed in the presence of neutrophil infiltration into the umbilical vessel walls or Wharton's jelly. AF WBC count was analyzed in a hemocytometer chamber. Nonparametric statistics were used for data analysis. Results. Funisitis was present in 4% (30/832) of cases. A positive AF culture was more common in cases with funisitis than in those without funisitis (17% vs. 5%; p < 50.05). Patients with funisitis had a significantly higher median AF WBC count than those without funisitis (median > 1000 cells/mm(3) vs. median 2 cells/mm(3); p < 0.001). The frequency of funisitis and of a positive AF culture was 1% in women without labor and with intact membranes and the frequencies and the median AF WBC count increased in the presence of labor or rupture of membranes. Conclusion. Funisitis is present in 4% of women at term and is associated with microbial invasion of the amniotic cavity (MIAC) and inflammation as reflected by increased AF WBC count.